A wide variety of processes are known in the art for the preparation of geranyl chloride. The compound can be prepared from myrcene by hydrohalogenation in the presence of a Cu catalyst (U.S. Pat. Nos. 3,016,408 and 2,871,271). It can also be prepared from linalool by reaction with SOCl.sub. 2, PCl.sub. 3, PCl.sub. 5, COCl.sub. 2, or HCl. Geraniol has also been used extensively as the starting material, most notably by treatment with PCl.sub. 3 or PCl.sub. 5 [L. Ruzicka, Helvetica Chim. Acta 6, 483-92 (1923)], and by treatment with a mixture of methanesulfonyl chloride, lithium chloride and dimethylformaide [E. W. Collington and A. I. Meyers, J. Org. Chem 36 (20), 3044 (1971)].
Many of the above reactions give extensive rearrangement products including elimination products. Others are costly and impractical as commercial processes.
The process of the present invention provides the advantage of favorable process economics, and produces the desired product in very high purity and yields.